The new ads on Zynga.com don't represent the stealth launch of a Facebook Ad Network, at least according to official sources. In fact, as Josh Constine at TechCrunch reports, this agreement was laid out in Facebook's S-1 documents before it went public, so it should come as no surprise. It's a revenue-sharing agreement between Facebook and Zynga, its longtime partner in all manner of time-wasting games, and they both insist that's all it is.
Facebook's PR statement is this: "We have had a close relationship with Zynga for a number of years and we think we can deliver value to Zynga and to the people playing their games by showing the same ads that they see on Facebook. We will not be showing ads on other sites at this time." (emphasis added)
It may not be here "at this time," but Facebook's ability to track its logged-in users around the Web is well known. If, as industry watchers have long expected, Facebook launches an ad network for other sites, it would quickly upset the balance of power on the ad-supported Web.